Improvement in book-supports



' J. & R. LAMB.

`BooK sUPPoRTs. No.187,393. Patented Feb. 13, 1877.

UNITED STATES PATENT @Prier JOSEPH LAMB AND RICHARD LAMB, OF' NEW YORK,N. Y.

IMPROVEMENT IN BOOK-SUPPORTS.

Specification forming part of Letters Patent N o. 187,393, datedFebruary 1?, 1577; application tiled March 17, 1876. V

To all whom it may concern Be it know that we, JOSEPH LAMB and RICHARDLAMB, of New York city, in the State of New York, have invented certainnew and useful Improvements relating to Adjustable Book-Supports7 ofwhich the following is a specification The invention may apply formusic-stands, and every variety of book-stand which is or may beadjustable vertically; but it is intended more especially for sacreddesks or pulpits. ln such, the book to be supported is usually heavy,and whenever the height requires adjustment, the operation frequentlyhas to be performed by a person possessing only moderate strength andlimited skill, and before the eyes of a large congregation.

We have devised a construction by which a sufficiently powerful springis introduced, having a suiicient range of motion, and the tension ofwhich should by preference be such as to considerably more than balancethe weight of the desk when unloaded, and to cause it to rise with someforce as soon as liberated by the binding-screw. We prefer to give thespring a force a little more than equal to the weight of the desk andbook combined, so that it will require a little force to press down thedesk to adjust it lower, even when loaded. In such case the manipulationbecomes easy, even to the most unskillful clergyman. On cautiouslyrelaxing the screw, the desk, instead of forcibly sinking, rises withmoderate force, which is easily resisted by one hand. If he wishes toraise it, he lets it move upward of itself'. If he wishes to lower it,he simply presses down with suficient force, and, having sunk it to thedesired position, again secures the binding-screw.

The following is a description of what we consider the best means ofcarrying out the invention:

The accompanying drawings form a part of this specification.

Figure 1 is vertical section of the upper portion of the standard orpost, with the desk depressed to nearly its lowest position. Fig. 2 is acorresponding section, with the desk elevated.

Similar letters of reference indicate like parts in both the gures.

Ais an upright post or standard, which may be provided with a suitablefoot, (not represented,) and lnade of any convenient height, and tastilydecorated or molded, carved, &c., except at the upper end, where theextension B from the desk B is adapted to match on and slide up anddown, as may be required. G is a binding-screw, provided with a milledhead, and tapped through a ring of metal, which is xed on and forms apart of the extension B of the desk. In the upper end of the standard Awe borea hole, a, in the line of the axis, ot' sufficient diameter andlength to re` ceive a long and strong coiled spring, D, which, when inplace, abuts at the lower end against the bottom of the hole, and at theupper en d against ,a suitable bearing on the under face ofthe desk B. Aslender rod, b, extends down from the center of the bearing of the deskto a considerable depth through the hollow interior of the spring.

The force of the spring D tends to lift the desk, while the gravity ofthe desk, and of a heavy book thereon, (not represented,) tends todepress it. It results that the forces are nearly balanced, but weprefer a slight excess of lifting force.

' In the operation of the desk, the screw G,

on being set up, holds it in any position del sired, like an ordinaryadjustable desk, but the spring D, instead of allowing gravity to sinkthe desk with force, balances it, and somewhat more than balances, sothat it is easy to change it with little strength or skill to anydesired elevation, when it may be again secured firmly by setting thebindingscrew C.

We believe it possible to attain very nearly the same end by reversingthe relative position of rods A and B, so that the smaller rod A shallextend down from the desk, and the larger rod which receives it shall bethe lower and stationary part. But we esteem it vitally essential to thesuccess of the device that the spring D be let into the interior of theinner and smaller rod, so that a great length of spring may be inserted.

We are aware that the desks and analogous articles have been adjustablysupported by the aid of springs, inclosed within a large cavity, andabutting against the end of a .rod inserted' adjustbly. Such We do notpost A a, the adjustable desk B, extension B',

spring D, and binding-screw C, as herein specified.

In testimony whereof we have hereuntoy set our hands.

JOS. LAMB. RICHARD LAMB.

Witnesses: Y

CHAs. A. BENEDICT, OsBoRN R. LAMB.

